Watershed Management in Drinking Water for Emergency: A Case of Lake Biwa - Yodo River System Takashi SASAKI*1& Daiji NAGASHIO** Yodo River Water Quality Committee 1. Background Lake Biwa - Yodo River water system is located in the middle west part of Japan and supports urban life and activities as one of the main water source for 14 million consumers in the Kansai area (Fig. 1). The water system is characterized by urbanization and developed industry in upstream area, at the same time, much use of domestic water in downstream area. This means the water is being reused so highly from upstream to downstream that there exist many kinds of risk factors to water safety. Drinking water supply utilities taking water from the river organize “Yodo River Water Quality Committee” for integrated source water quality management to cope quickly and systematically with source accidents. This paper describes outline of the Committee and its source monitoring for emergency. 2. Outline of Yodo River Water Quality Committee Fig. 2 shows yearly changes in raw water quality at Kunijima water treatment plant (WTP) of Osaka City, one of the largest utilities. Since the quality rapidly deteriorated due to increased domestic and industrial wastewaters in 1960s, downstream utilities were forced to take countermeasures for these problems. The utilities concluded that cooperative approach for integrated source quality management was the best way and established Yodo River Water Quality Committee in 1965, which is currently composed of ten utilities (Osaka Prefectural -, Osaka Municipal -, Moriguchi City -, Neyagawa City -, Hirakata City -, Suita City -, Amagasaki City -, Itami City -, Nishinomiya City - waterworks and Hanshin Water Supply Authority) (Pic. 1). Since then, the Committee has engaged in various activities for resource conservation including; * Technical administrator, Hanshin Water Supply Authority, 20-1 Nishi-okamoto 3-chome, Higashinada-ku, Kobe 658-0073, Japan (e-mail: [email protected]) ** Director of water quality, Hanshin Water Supply Authority, 20-1 Nishi-okamoto 3-chome, Higashinada-ku, Kobe 658-0073, Japan (e-mail: [email protected]) Kansai area N 0 30 km Lake Biwa Kyoto Tokyo Yodo River Osaka Fig. 1 Outline of Lake Biwa - Yodo River water system 1.5 15 200000 KMnO過ﾏﾝｶﾞﾝ酸ｶﾘｳﾑ消費量4 comsumption Ammoniaｱﾝﾓﾆｱ態窒素 (mg/Ｌ) 150000 BOD ) 1.0 Ｌ 10 一般細菌Standard plate count (mg/ 100000 comsumption comsumption 4 0.5 5 Ammomia Ammomia KMnO 50000 Standard Plate Count (CFU/mL) Count Plate Standard ＢＯＤ, ＢＯＤ, 0 0 0 1897 1907 1917 1927 1937 1947 1957 1967 1977 1987 1997 FY Fig. 2 Yearly changes in water quality of Yodo River Pic. 1 Board Meeting of Yodo River Water Quality Committee ･Regular monitoring of source quality ･Research and investigation for source quality management ･Advocating activities for pollution control ･Awareness raising for resource conservation ･Establishment of information networks for emergency control 3. Water Source Monitoring for Emergency (1) Information Networks for Emergency Control In case of source accident, river administrator provides the Committee with information reported from the finder. Then the Committee informs all the members of the accident according to emergency information networks rules (Fig. 3). Fig. 4 shows changes in the number of source accidents. The number has been increasing since 1990 after brief decline at around 1980. Severe accidents which directly affect waterworks has been decreasing, on the other hand, the ratio of oil spill accidents has been increasing in recent years. The Committee has periodically appealed to administrative bodies to supervise the causative facilities, and achieved successful results. An oil spill accident in October 2003 provides a good example. The accident occurred at one of tributaries of Yodo River and affected downstream utilities. One of WTPs was forced to stop water intake for four hours and six of WTPs had to reduce water intake, absorb oil, or use powdered activated carbon to cope with the spilled oil. Quick circulation of information followed by proper response to the accident prevented finished water from being contaminated. After that, four affected utilities claimed compensation from the causative facility that the Committee identified. (2) Organizing Watershed Data Differences in the arrival time of contaminants from accident spot to intake points are useful when accidents happen. The Committee developed “Arrival time display system in Yodo River” based on observed time considering the effect of river shape and estuary barrage. The Committee also created factories’ database in the basin named “Environmental map” (Fig. 5) containing their locations and harmful chemicals used to quickly respond to source accidents. The map can numerically display contamination risk by harmful chemicals in the whole area utilizing the stored data. Accident Finder River Administrator Neyagawa City Osaka Prefectural Waterworks Waterworks Accident Finder Hirakata City Osaka Municipal Waterworks Waterworks Suita City Hanshin Water Waterworks Supply Authority Moriguchi City Itami City Waterworks Waterworks Amagasaki City Nishinomiya City Waterworks Waterworks Fig. 3 Information networks for emergency control 40 the others 35 fish nosing or kill 30 cyanide unpleasant odor 25 color oil 20 15 10 The number of accidents of number The 5 0 1959 1963 1967 1971 1975 1979 1983 1987 1991 1995 1999 2003 FY Fig. 4 The number of water source accidents in Lake Biwa – Yodo River water system Fig. 5 Part of environmental map in Yodo River basin 4. Summary Delay in the response to accidents in the source may cause serious damages in the social life, since the systems of waterworks being consisted of series of facilities from source to consumers’ tap and the systems are not free from vulnerability. In order to ensure water safety, it is important to detect source accidents as quickly as possible and then respond to them properly. The Yodo River Water Quality Committee, a group of downstream water utilities of Yodo River being exposed to the high risk of accidents, jointly monitors water source and engages in resource conservation activities. These efforts have been successfully assuring safety of drinking water so far. There are other efforts in regard to watershed management. Review Panel on Water Cycle Dysfunction Risk in Emergency, a panel established by government ministries, is discussing cross-sectoral measures to avoid or reduce water quality risk in case of earthquake, whose target area includes Yodo River basin. In addition, Kansai Waterworks Association consisted of eight major utilities in the Kansai area has jointly been studying on “Kansai version of Water Safety Plan”. The developing process will include scientific evaluation on risk factors about their characteristics and risk levels. The goal is to contribute to planning of source quality management and drinking water treatment. Watershed Management in Drinking Water for Emergency: A Case of Lake Biwa - Yodo River System Yodo River Water Quality Committee Takashi SASAKI, Daiji NAGASHIO Lake Biwa – Yodo River Water System Lake Biwa Kyoto City Yodo River Japan Osaka City Osaka Bay Okinawa 1 Urbanization of Upstream Changes in Raw Water Quality at Kunijima WTP Establishment of Yodo River Water Quality Committee KMnO4 consumption (mg/L) Bacteria count (cfu/mL) 20 200000 Musty Odor KMnO4 consumption 15 150000 Bacteria count 10 100000 5 50000 0 0 1900 10 20 30 40 50 60 70 80 90 Year 2 Establishment of Yodo River Water Quality Committee • Why organized ? – Urbanization and industrial development in upstream area – Deterioration of water quality in Yodo River • When established ? – 1965 • What purpose ? – Cooperative approach for integrated source water quality management Members • Osaka Prefectural - • Osaka Municipal - • Moriguchi City - • Neyagawa City - • Hirakata City - Total Capacity (plan) 7.2 million m3/d • Suita City - Served population • Amagasaki City - 11 million • Itami City - • Nishinomiya City Waterworks • Hanshin Water Supply Authority 3 Board Meeting Activities Regular monitoring Research and investigation Awareness raising (Annual lecture meeting) Advocating activities Information networks for emergency control 4 Regular Monitoring of Source Quality • Monthly monitoring conducted with cooperative system • 20 Monitoring points • Over 160 of monitoring Items • Results summarized as annual reports Research and Investigation • Several working groups for special task urgently needed Assignment ¾Musty odor at Lake Biwa ¾Precursors of trihalomethanes and agricultural chemicals in the water source ¾Development of useful tools for quick response to water source accidents 5 Advocating Activities for Pollution Control NationalNational government government Request Ministry of - Health, Labour and Welfare - Agriculture, Forestry and Fisheries YodoYodo River River Water Water QualityQuality Committee Committee - Economy, Trade and Industry - Land, Infrastructure and Transport - the Environment Request LocalLocal government government Osaka prefecture Kyoto prefecture and city Other 6 administrative bodies Awareness Raising for Water Resource Conservation • Posters and brochures • Annual lecture meeting 6 Water Source Monitoring for Emergency • Information-sharing – Monitoring of source quality – Source accident – Research and investigation – Risk factors • Control of pollutant source – Advocating activities – Awareness raising Information Networks for Emergency Control Accident Finder River Administrator Neyagawa Osaka City